Bidirectional lever arm clutch

ABSTRACT

A bidirectionally rotatable mechanism for separately driving two unidirectionally rotatably driven devices is disclosed. The mechanism includes a bidirectionally driving external rim that encompasses a bidirectionally driven internal device that supports two oppositely axially aligned lever arms. The external rim is pin coupled to slots in the ends of the lever arms such that rotation of the external rim in the clockwise or counterclockwise direction rotates one or the other of the lever arms into axial alignment and also rotates the internal device in the like clockwise or counterclockwise direction. The one axially aligned lever arm then engages an associated unidirectionally rotatably driven member.

United States Patent [21] App]. No.2 239,084

I Hanson 1 Apr. 17, 1973 [5 1 BIDIRECTIONAL LEVER ARM 3,495,789 2/1970 Gerfast ..242/201 CLUTCH 3,623,680 1 H1971 Egnaczak ..242/201 [76] Inventor: Kent W. Hanson, c/o Univac Park, 1

PO. Box 3525, American Fork, gnmary Z J NE Hermann Utah 55165 ttorneyennet race et a1.

[22] Filed: Mar. 29, 1972 [57] ABSTRACT A bidirectionally rotatable mechanism for separately driving two unidirectionally rotatably driven devices is 52 US. Cl. ..192/4s.92, 192/46, 192/51, disclosed- The mechanism imludes a bidireclionally 74577 R, 242/201 driving external rim that encompasses a bidirectionally 511 Int. Cl ..Fl6d 41/12, G03b 1/12 driven internal device that supports two pp y [58] Field of Search ..192/4s.92, 46, 51, ially aligned lever The external rim is p 192/43.l; 74/577 S, 577 R, 812; 242/201 pied to slots in the ends of the lever arms such that rotation of the external rim in the clockwise or'coun- [56] References Cited terclockwise direction rotates one or the other of the lever arms into axial alignment and also rotates the in- UNITED STATES PATENTS ternal device in the like clockwise or counter- 344i160 6/1336 Brownson 192/411 x clockwise direction. The one axially aligned lever arm 547,386 10/1895 Stewart ....192/46 X then engages an associated unidirectionally rotatably 684,482 10/1901 Walters.... ..192/46 driven member. 1,563,742 12/1925 Hansen..... ....74/8l2 X 2,866,109 12/1958 Watson ..192/46 X 6 Claims, 3 Drawing Figures 1 54 iii-ioes e2 :8

BIDIRECTIONAL LEVER ARM CLUTCH BACKGROUND OF THE INVENTION In the magnetic tape read/record prior art there have been many designs for driving magnetic tape across the read/record head; such designs generally are of twoclasses in which the tape is pulled across the read/record head by applying the main propelling force directly to the tape as by a capstan and pinch roller or by applying the main propelling force directly to the pulling read/record or rewind reel. In the field of miniature cassette type recorders it may be desirable that all propelling force by applied directly to the pulling read/record or rewind reel. As rapid reversal of tape direction is desirable, direction reversal mechanisms are required. Such mechanisms can involve elaborate mechanical arrangements for achieving reversal of the direction of rotation of the reel-see G. Pabst U.S. Pat. No. 3,475,563. The present invention is directed toward an improved drive mechanism for achieving such bidirectional rotation of the reels.

SUMMARY OF THE INVENTION The present invention is directed toward a mechanism that includes a clutch-like device for selectively driving either the read/record or rewind reel of a cassette tape system by means of a bidirectionally rotatable electric motor. The mechanism includes a rotatable external rim-like pulley that is driven in the clockwise or counterclockwise by a belt and bidirectionally rotatable electric motor. Internal to the external rim is a rotatable device that supports two axially oppositely directioned lever arms on diametrically opposed external surfaces. The lever arms are rotatably pinned to the internal device to oppositely rotate into substantial axial alignment the external rim and internal device as determined by associated stops on the internal device. Pins on the external rim couple the lever arms on the internal device through slots on the ends of the lever arms such that rotation of the external rim rotates the two lever arms about their axes of rotation; when the external rim is rotated in, e.g., the clockwise direction a first lever arm is rotated in axial alignment while the second lever arm is rotated out of axial alignment, and, conversely, when the external rim is rotated in the, e.g., counterclockwise direction the second lever arm is rotated in axial alignment while the first lever arm is rotated out of axial alignment. When one of the lever arms is in axial alignment it engages a stop in an associated rotatable member; thus, the associated rotatable members are separately driven in opposite directions. The rotatable members then drive the associated read/record or rewind reels of the tape cassette.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a magnetic tape cassette unit incorporating the present invention.

FIG. 2 is a partially cut-away view of the magnetic tape cassette unit of FIG. 1 taken along line 2-2.

FIG. 3 is a partially cut-away view of the magnetic tape cassette unit of FIG. 1 taken along line 3--3.

LII

DESCRIPTION OF THE PREFERRED EMBODIMENT With particular reference to FIG. 1 there is presented a plan view of a magnetic tape cassette unit which incorporates the mechanism of the present invention. Magnetic tape cassette unit 10 includes magnetic tape cassette l2 and the read/record head assembly 14 for reading out of and writing into the magnetic tape held on the read/record and rewind reels of magnetic tape cassette 12. The magnetic tape as held on the read/record and rewind reels is driven past read/record head 14 by means of electric motor 16 and its associated driving chain. This driving chain includes a belt 18 rotatably coupled to driving pulley 17 and idling pulley 20 to which is integrally formed a second idling pulley 22. Belt 24 is, in turn, rotatably coupled to idling pulley 22 and mechanism 26 which is a bidirectionally driven, by bidirectionally rotatable motor 16, rotatable mechanism for separately unidirectionally driving read/record pulley 28 in a, e.g., counterclockwise direction or rewind pulley 30 in a, e.g., counterclockwise direction as by belt 32.

With particular reference to FIGS. 2 and 3 there are shown partially cut-away views of the magnetic tape cassette unit 10 of FIG. 1 taken along lines 2-2 and 3-3. The present invention is directed toward the mechanism 26 that includes a clutch-like device for selectively driving either the read reel sprocket 40 or the rewind reel sprocket 42 of the magnetic tape cassette unit 10 by means of the bidirectional electric motor 16 and the associated pulleys and belts. Mechanism 26 includes a rotatable external rim-like pulley 44 that is driven in a clockwise or counterclockwise direction by belt 24. lnternal to the external rim 44 is a rotatable internal device 46 that supports two axially oppositely directioned lever arms 48 and 49 (see FIG. 3) on diametrically opposed parallel external supporting planar surfaces 50 and 51 by their associated pins 52 and 53. The lever arms 48 and 49 are rotatably pinned by pins 52 and 53 to the device 46 to oppositely rotate in substantial axial alignment with, i.e., parallel to axis 60, the external rim 44 and device 46 as determined by their associated stops 54 and 55 on the surfaces 50 and S1 of device 46.

Pins 56 and 57, which are integral with the external rim 44, couple the lever arms 48 and 49 on the device 46 through their associated slots 58 and 59 on the ends of the lever arms 48 and 49 such that rotation of external rim 44 rotates the two lever arms 48 and 49 about their axes of rotation, i.e., pins 52 and 53, respectively; when the external rim 44 is rotated in, e.g., the counterclockwise direction as seen from FIG. 1, the first lever arm ,48 is rotated into axial alignment, i.e., parallel to axis 60 of mechanism 44, while the second lever arm 49 is rotated out of axial alignment and, conversely, when the external rim 44 is rotated in the, e.g., clockwise direction as seen from FIG. 1, the second lever arm 49 is rotated into axial alignment whilethe first lever arm' 48 is rotated out of axial alignment. When one of the lever arms 48 or 49 is in axial alignment, i.e., parallel to axis 60 of mechanism 26, it engages an associated stop 62 or 63 in an associated rotatable member 28--see FIG. 2--or pulley 64-see FIG. 3-; thus, the associated rotatable member 28 or pulley 64 are separately alternatively driven in opposite, e.g., clockwise or counterclockwise directions. The member 28 through shaft 66 then drives the read/write sprocket 40 and the associated reel while the pulley 64 through belt 32 and pulley 30 drives the rewind sprocket 42 and the associated reel.

In the illustrated embodiment of FIGS. 2 and 3, external rim 44 is illustrated as being driven in a counterclockwise direction, as seen from FIG. 1; thus, in FIG. 2 lever arm 48 is shown in solid lines, in axial alignment with axis 60 and in engagement with stop 62 in member 28 for driving member 28 in the counterclockwise direction. Member 28, in turn, drives shaft 66 and read/write sprocket 40 in a counterclockwise direction. Corresponding lever arm 49, on the back side of device 46 from lever arm 48, is shown in solid lines in FIG. 3 as being out of axial alignment with axis 60 and not in engagement with its associated stop 63 such that pulley 64 receives no rotative driving force from device 46.

If external rim 44 were to be suddenly driven in the reverse or clockwise direction it would rotate in a clockwise direction with respect to device 46 such that the pins 56 and 57 would rotate the associated lever arms 48 and 49 about their associated pivot points formed by pins 52 and 53, respectively. Lever arm 48 would then be rotated out of axial alignment and out of engagement with stop 62 in member 28 while lever arm 49 would then be rotated into axial alignment and into engagement with stop 63 of pulley 64. Thus, now in the new clockwise rotational direction of rim 44, rim 44, through pin 57, lever arm 49 and stop 63, would drive pulley 64 in the like clockwise direction of rotation. Pulley 64 by means of belt 32, pulley 30, shaft 68 and rewind sprocket 42 would then drive the associated rewind reel to rewind the magnetic tape in tape cassette l2. correspondingly, the clockwise rotation of rim 44 would, as stated above, rotate lever arm 48 out of axial alignment and out of engagement with stop 62 in member 28 such that read/record sprocket 40 receives no rotative driving force from device 46; this mode of operation is illustrated by the positions of lever arms 48 and 49 in their dash line orientations of FIGS. 2 and 3.

What is claimed is:

1. A bidirectionally rotatable mechanism for driving two unidirectionally rotatable elements, comprising:

a bidirectionally rotatable external rim;

a bidirectionally rotatable internal device having two diametrically opposed surfaces, said internal device internal to said external rim and rotatable about the same primary axis;

first and second lever arms rotatably mounted on first and second ones, respectively, of said two diametrically opposed surfaces, said first and second lever arms being alternatively rotatable into substantial alignment with said primary axis but oppositely directioned;

first and second coupling means affixed to said external rim for alternatively rotating said first and second lever arms, respectively, into substantial alignment and substantial misalignment, respectively, or vice versa, with said primary axis;

- first and second unidirectionally rotatable elements rotatable in opposite directions about said primary axis and located adjacent to opposite ends of said internal device, each of said first and second unidirectionally rotatable elements including associated stop means for alternatively engaging said first or said second lever arm when said first or said second lever arm is in its substantial axial alignmentwith said primary axis.

2. The mechanism of claim 1 in which said two diametrically opposed surfaces are flat, parallel surfaces equal distances from said primary axis.

3. The mechanism of claim 1 in which said first and second lever arms each have slotted ends for engaging said first and second coupling means.

4. The mechanism of claim 1 in which said first and second lever arms rotate in a plane parallel to their associated first and second diametrically opposed surfaces.

5. The mechanism of claim 1 in which said first unidirectionally rotatable element is mounted on a shaft that passes through said internal device and said second unidirectionally rotatable element for driving a third unidirectionally rotatable element on the far side of said second unidirectionally rotatable element.

6. The mechanism of claim 1 in which said first and second lever arms extend beyond the associated ends of said internal device and into said associated first and second unidirectionally rotatable elements for making contact with said associated stop means only when said first and second lever arms are alternatively rotated into substantial alignment with said primary axis 

1. A bidirectionally rotatable mechanism for driving two unidirectionally rotatable elements, comprising: a bidirectionally rotatable external rim; a bidirectionally rotatable internal device having two diametrically opposed surfaces, said internal device internal to said external rim and rotatable about the same primary axis; first and second lever arms rotatably mounted on first and second ones, respectively, of said two diametrically opposed surfaces, said first and second lever arms being alternatively rotatable into substantial alignment with said primary axis but oppositely directioned; first and second coupling means affixed to said external rim for alternatively rotating said first and second lever arms, respectively, into substantial alignment and substantial misalignment, respectively, or vice versa, with said primary axis; first and second unidirectionally rotatable elements rotatable in opposite directions about said primary axis and located adjacent to opposite ends of said internal device, each of said first and second unidirectionally rotatable elements including associated stop means for alternatively engaging said first or said second lever arm when said first or said second lever arm is in its substantial axial alignment with said primary axis.
 2. The mechanism of claim 1 in which said two diametrically opposed surfaces are flat, parallel surfaces equal distances from said primary axis.
 3. The mechanism of claim 1 in which said first and second lever arms each have slotted ends for engaging said first and second coupling means.
 4. The mechanism of claim 1 in which said first and second lever arms rotate in a plane parallel to their associated first and second diametrically opposed surfaces.
 5. The mechanism of claim 1 in which said first unidirectionally rotatable element is mounted on a shaft that passes through said internal device and said second unidirectionally rotatable elemeNt for driving a third unidirectionally rotatable element on the far side of said second unidirectionally rotatable element.
 6. The mechanism of claim 1 in which said first and second lever arms extend beyond the associated ends of said internal device and into said associated first and second unidirectionally rotatable elements for making contact with said associated stop means only when said first and second lever arms are alternatively rotated into substantial alignment with said primary axis. 